Production of sulfonic acids



Patented Dec. 30, 1952 PRODUCTION OF SULFONIC ACIDS Holger G. H. Erdtman, Stockholm Sweden No Dra ng. Application July 26, 1949, Serial No.

roams; In Sweden Julyi29,:148 '3 fi ahns- (c1. 261 :3199

The r sen hiv nt cnre ates tethe prote tion of sulphonic acids of thege erfil zi fimlllfi in which rep es n s a ar mat c rad ca w ic may be heterocyclic or ocyclic, Such su homo acids Show difierent kindsof bio ogic act Hitherto the said sulphonic acids have mainly been pr a y reac in h .halceenid 9 th radical which is to be bound to th vsulphonic group with a ul ite- However the O n halogenids used aslstarting material a e Oft n difficuh to oduce r unstable! w ich h the to n an obs ac la ain th .i more the It i t main h i' cto the p esen .ehtihh to find a new way of producing the said sulp I onic acids by which the previous-diificulties are voided.

This object and other advantages which will be evident from the following description are i ed ac o n to he invention by s ng as a starting material a special kinder nitrogen compound of the organic radical of the sulphonic acid to be produced and reacting such nitrogen compound with a sulphite, preferably in the presence of a diluent suchas water.

The particular aromaticnitrogen compounds to be used are aromatic aminomethyl derivates as they contain or derive from the group R.CH2.N. in wh ch R is an aromatic ,isocyclic or heterocyclic radical and the nitrogen atom has basic nature.

The aminomethyl compounds to be used have the general formula.

R1 R.CH2.N/

R2 in which R is the same radical as above stated and R and It are hydrogen or alkyl groups. The substituents R and R may also be parts of a ring such as the piperidine or morpholine rings. The good results according to the invention are, however, also obtained if the group R.CH2.N is a part of a quaternary ammonium compound of the general formula.

in which R is the same group as before X a negative radical and R R and R are members of the group consisting of hydrogen and alkyl groups and in which two of the substituents R, R and B may be interconnected in a ring such as in piperidine or morpholine.

All ese nitro en com ounds. eierred toahove may easily be produced by the so called Mannich reaction (see Organic Reactions by Roger Adams, W. E. Bachmann, L. F. Fieser, J. R. Johnson and H. R. Snyder, vol. 1, New York 1942, P- 3 nd .f l ia l c ns st neonate ee mag a r o sc pte -y u ua ly th ld h d Q 5.. 7 hydrogen atom 1 c ep All the se above mentioned o aminometh l nt-a es h l'li "t i 2592'!!! 9i ami compounds or in the igrrn theGor-responding ua y ammon um fc iimvh s be found to have the common property that .they

easily react with a sulphite whereby'the bond between nitrogen andthe methylene group bound to the aromatic radical-R is broken and the nitrogen containing radical is substituted by a sulhonicgroup.

The sulphites used according to the inyenticn may be either neutral .or.,a'cid; the neutral sulphites being preferred as they give better yields.

The following examples are given for the purpose of illustrating the invention only and not for limiting the same.

Example I indolyl-methane-sulphonic acid crystallizes. The

compound was recrystallized in water. The yield was quantitative. The p-naphthylamine salt of the sulphonic acid melts at 228 C.

Example II solution the barium salt of 2-hydro-5-methylbenzyl-sulphonic acid crystallized. The crystallization may be accelerated or made more complete by the addition of an organic solvent intermiscible with water such as ethanol.

I have also carried out the reactions described in the above examples with other compounds such as ,9-(N-diethyl-amino-methyl) -indol the general formula R.CH2.SO3H in which R is.

an aromatic radical, consisting in reacting, in the presence of a solvent, an inorganic sulphite with a compound of the general formula R1 1 R.CHZ.N/

in which R is an aromatic radical and R and R are members of the group consisting of hydrogen 'alkyl 'groups and methylene groups of a heterocyclic ring containing not more than five methylene groups and in which the nitrogen atom is of basic nature.

2. The method as defined in claim 1 in which R and R are alkyl groups.

3. The method as defined in claim 1 in which the compound is supplied to the reaction in the form of a quaternary ammonium compound.

4. The method as defined in claim 1 in which the compound R.CH2.N

R2 is supplied to the reaction in the form of a quaternary ammonium compound and in-which R and R are methylene members of a heterocyclic ring.

'4 5. The method as defined in claim 1 in which R is an isocyclic radical.

6. The method as defined in claim 1 in which the group is an integral part of a morpholino group.

7. The method as defined in claim 1 in which the group is an integral part of. a piperidino group.

8.. The method of producing B-indolyl-methanv, sulphonic acid in the form of it sodium salt in which gramine is heated with sodium sulphite in the presence of water after which the sodium salt of the sulphonic acid is crystallized out of the solution by cooling.

9. The method of producing 2-hydroxy-5- methyl-benzyl-sulpho-nic acidin the form of its barium salt, which consists in heating a mixture of 2-N-dimethyl-aminomethyl-4-methylwphenol, sodium sulphite and water till the reaction is completed, concentrating the reaction mixture and extracting said concentrate with ether, the remaining water phase then being passed through a hydrogen saturated cation exchanger, the resulting filtrate being treated with barium carbonate, filtered, concentrated, and cooled whereby the barium salt of the 2-hydroxy-5-methylbenzyl sulphonic acid is crystallized out of the solution. a

HOLGER G. H. ERDTMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Wieland et al., Annalen, 561 pp. 47-52 (1948). 

1. THE METHOD OF PRODUCING SULPHONIC ACIDS OF THE GENERAL FORMULA R.CH2.SO3H IN WHICH R IS AN AROMATIC RADICALS, CONSISTING IN REACTING, IN THE PRESENCE OF A SOLVENT, AN INORGANIC SULPHITE WITH A COMPOUND OF THE GENERAL FORMULA 